#include<stdio.h>
#include<math.h>
int main()
{
	int i,count;
	printf("There are invertable primes with 4digits:\n");
	for(count=0,i=1001;i<9999;i+=2)
	
		if(num(i))
			printf(count%9?"%3d:%d":"%3d:%d\n",++count,i);
}
int num(int number)
{
		int j,i;
		if(!ok(number))
			return 0;
		for(i=number,j=0;i>0;i/=10)
			j=j*10+i%10;
		if(number<j)
			if(!ok(j))
				return 0;
			else
				return 1;
		else
			return 0;
	}
	int ok(int number)
	{
		int i,j;
		if(number%2==0)
			return 0;
		j=sqrt((double)number)+1;
		for(i=3;i<=j;i+=2)
			if(number%i==0)
				return 0;
		return 1;
	}

